Various types of transparent armoring products are known. Examples of such products are shown in U.S. Pat. No. 3,380,406, U.S. Pat. No. 3,624,238 and U.S. Pat. No. 4,594,290. Transparent armoring products are useful in various environments in which it is desirable to protect personnel from bullets, shrapnel and other projectiles while at the same time permitting personnel to see through the protective structure. For example, transparent armoring products can be utilized by banks at drive-up teller windows. Transparent armoring products are also useful in mobile applications. For example, transparent armoring products can be used instead of traditional glass on military vehicles. This permits the vehicle driver and occupants to directly observe the environment outside the vehicle while protecting them from bullets, shrapnel and other projectiles. Depending on the weight of the transparent armoring products, they can also be useful for personal protection devices such as face shields for police officers or military personnel.
In one embodiment of the present invention, a transparent armor structure includes a first layer of a first material, a second layer of a second material, the second layer positioned adjacent to the first layer, a third layer of a third material, an air gap between the second and third layers, a fourth layer of the second material, the fourth layer positioned adjacent to the third layer, a fifth layer of the third material, the fifth layer positioned adjacent to the fourth layer, a sixth layer of the second material, the sixth layer positioned adjacent to the fifth layer, a seventh layer of the third material, the seventh layer positioned adjacent to the sixth layer, an eighth layer of the second material, an air gap between the seventh and eighth layers and a ninth layer of a fourth material, the ninth layer positioned adjacent to the eighth layer. The third layer includes a first surface, a second surface opposite the first surface and four edges extending between the first and second surfaces. The first and third edges have constant thicknesses and are disposed opposite each other. The thickness of the third edge is less than the thickness of the first edge. The second and fourth edges are disposed opposite each other. The fifth layer includes a first surface, a second surface opposite the first surface and four edges extending between the first and second surfaces. The first edge is located opposite the third edge and the second edge is located opposite the fourth edge. All four edges have varying thicknesses. The seventh layer includes a first surface, a second surface opposite the first surface and four edges extending between the first and second surfaces. The first and third edges have constant thicknesses and are disposed opposite each other. The thickness of the third edge is less than the thickness of the first edge. The second and fourth edges are disposed opposite each other. In one embodiment, the first material is a first type of glass and the second material is a second type of glass. In another embodiment, the third material is a polyurethane. According to another embodiment of the invention, the fourth material is a polycarbonate.
In another embodiment of the present invention, the thickness of the first edge of the third layer is substantially the same as the thickness of the first edge of the seventh layer. In another embodiment, the first edge of the seventh layer is oriented at a 90 degree angle with respect to the first edge of the third layer. The first edge of the seventh layer can be oriented at a 90 degree angle with respect to the first edge of the fifth layer. According to another embodiment of the invention, the dimensions of the third layer are substantially the same as the dimensions of the seventh layer and the combined thickness of the first edge of the third layer, the first edge of the fifth layer and the fourth edge of the seventh layer is constant when the first edge of the third layer is parallel to the first edge of the fifth layer and the first edge of the seventh layer is disposed at a 90 degree angle to the first edge of the third layer.
In yet another embodiment of the invention, the second surface of the third layer faces the first surface of the fifth layer and is parallel to the first surface of the fifth layer, the second surface of the fifth layer faces the first surface of the seventh layer and is parallel to the first surface of the seventh layer and the first surface of the third layer is parallel to the second surface of the seventh layer.
In another embodiment of the present invention, a transparent armor structure includes first, second and third layers. The first layer has a first surface, a second surface opposite the first surface and four edges extending between the first and second surfaces. The first and third edges are opposite each other and are of constant thickness along their lengths, with the thickness of the first edge being greater than the thickness of the third edge. The second and fourth edges are opposite each other and vary in thickness along their lengths. The second layer has a first surface, a second surface opposite the first surface and four edges extending between the first and second surfaces. The first edge is opposite the third edge and the second edge is opposite the fourth edge. All four edges vary in thickness along their lengths. The third layer has a first surface, a second surface opposite the first surface and four edges extending between the first and second surfaces. The first and third edges are opposite each other and are of constant thickness along their lengths, with the thickness of the first edge being greater than the thickness of the third edge. The second and fourth edges are opposite each other and vary in thickness along their lengths. In one embodiment, the dimensions of the first layer are substantially the same as the dimensions of the third layer. In another embodiment, the thickness of the second edge of the first layer at any location along its length is substantially the same as the thickness of the fourth edge at the same location along its length.
According to another embodiment of the present invention, the thickness of the first edge of the second layer at a given distance from the fourth edge of the second layer is substantially the same as the thickness of the second edge of the second layer at the same distance from the third edge of the second layer. Additionally, the thickness of the third edge of the second layer at a given distance from the second edge of the second layer is substantially the same as the thickness of the fourth edge of the second layer at the same distance from the first edge of the second layer.
In another embodiment of the invention, the second surface of the first layer faces the first surface of the second layer and is parallel to the first surface of the second layer, the second surface of the second layer faces the first surface of the third layer and is parallel to the first surface of the third layer and the first surface of the first layer is parallel to the second surface of the third layer.
In another embodiment of the present invention, a transparent armor structure includes a first layer having a first planar surface and a second planar surface of substantially the same configuration as the first planar surface. The second planar surface is located opposite the first planar surface and is oriented such that it is not parallel to the first planar surface and such that corresponding locations on the first and second planar surfaces are displaced approximately 90 degrees from each other. In one embodiment, the armor structure further includes second and third layers. The second layer has a first surface and a second surface facing the first surface of the first layer and parallel to the first surface of the first layer. The third layer has first and second surfaces. The first surface faces the second surface of the first layer and is parallel to the second surface of the first layer. The first surface of the second layer and the second surface of the third layer are parallel.
Other features of the present invention will be apparent to those skilled in the art from the following detailed description of embodiments of the invention and the accompanying drawings.